android - StaggeredGridLayoutManager returns wrong verticalScrollOffset -

-

i'm doing same here (https://github.com/kmshack/android-parallaxheaderviewpager), recyclerview in tabs.

recyclerview in 1 tab has items big height , first 1 not visible under header. @ point call recyclerview's computeverticalscrolloffset() (that calls staggeredgridlayoutmanager's method) , returns wrong values. if change header height make first item visible i'm getting right values.

is there known solution/fix this?

p.s. use linearlayoutmanager , right values if first item not visible under header

i believe error findfirstvisibleposition() , findlastvisibleposition() used in computescrolloffset() function arguments. if use equal row height computeverticalscrolloffset() returns weird numbers. if replace them recyclerview.getchildat(0) , recyclerview.getchildat(recyclerview.getchildcount() - 1) works.

so can write our own function:

view firstitemview = recyclerview.getchildat(0); view lastitemview = recyclerview.getchildat(recyclerview.getchildcount() - 1);  int firstitem = recyclerview.getchildlayoutposition(firstitemview); int lastitem = recyclerview.getchildlayoutposition(lastitemview); int itemsbefore = firstitem;  int laidoutarea = recyclerview.getlayoutmanager().getdecoratedbottom(lastitemview) - recyclerview.getlayoutmanager().getdecoratedtop(firstitemview); int itemrange = lastitem - firstitem + 1; float avgsizeperrow = (float) laidoutarea / itemrange;  int offset = (int) (itemsbefore * avgsizeperrow + recyclerview.getlayoutmanager().getpaddingtop() - recyclerview.getlayoutmanager().getdecoratedtop(firstitemview));

Comments

Post a Comment

Popular posts from this blog

java - Custom OutputStreamAppender not run: LOGBACK: No context given for <MYAPPENDER> -

-
i wish write custom appender on basis of outputstreamappender . wrote following class package tests; import java.io.ioexception; import java.io.outputstream; import ch.qos.logback.core.outputstreamappender; public class myappender<e> extends outputstreamappender<e> { public myappender() { system.out.println("myappender created"); setoutputstream(new outputstream() { @override public void write(int b) throws ioexception { throw new unsupportedoperationexception(); } }); } } then wrote following runner: package tests; import org.slf4j.loggerfactory; import ch.qos.logback.classic.logger; public class runner { private static final logger log = (logger) loggerfactory.getlogger(runner.class); public static void main(string[] args) { //log.addappender(new myappender<iloggingevent>()); log.info("hello world"); } } finall...
Read more

java - UML - How would you draw a try catch in a sequence diagram? -

-
Image
is there standard way of drawing try catch sequence diagrams? i've made attempt based on this feel end result doesn't feel right. code diagram based around: public static void save () { try { filehandle filehandle = gdx.files.external(file); filehandle.writestring(boolean.tostring(constantshandler.soundenabled)+"\n", false); (int = 0; < 5; i++) { filehandle.writestring(integer.tostring(constantshandler.highscores[i])+"\n", true); } } catch (throwable e) { } } my attempt note: know still need add loop. that's ok. fragments meant show conditional control flow in sequence diagram. superstructures puts limitations on use of fragments (see pp. 467 of ss2.1.1). should use critical region try part above. , option catch . however, keep telling can take quite freedom in using uml. it's language , such changes in life time. long reader ge...
Read more

c++ - No viable overloaded operator for references a map -

-
i trying use map can make tag names reference number. when try , use it, in code error (6 in total every time reference map): src/main.cpp:25:45: error: no viable overloaded operator[] type 'std::map<std::string, std::string>' const char* idcs = node.child_value(tagmap[3]); this code: #include "pugi/pugixml.hpp" #include <iostream> #include <string> #include <map> int main() { pugi::xml_document doca, docb; std::map<std::string, pugi::xml_node> mapa, mapb; std::map<std::string, std::string> tagmap {{"1", "data"}, {"2", "entry"}, {"3", "id"}, {"4", "content"}}; if (!doca.load_file("a.xml") || !docb.load_file("b.xml")) { std::cout << "can't find input files"; return 1; } (auto& node: doca.child(tagmap[1]).children(tagmap[2])) { co...
Read more